A docking station on which a portable data processing terminal is detachably mounted is known. A docking station of this kind, when a data processing terminal is mounted thereon, is provided with a power feeding function to feed an operating power of the relevant data processing terminal to the relevant data processing terminal, in many cases. The docking station provided with this power feeding function may feed power of such a high voltage as 19 V, for example, to the data processing terminal, in order to rapidly charge a battery incorporated in the data processing terminal.
In the above-described docking station, it is preferable that when the data processing terminal is demounted, application of a voltage for power feeding to a power feeding terminal which is in contact with a power source terminal at the data processing terminal side is stopped. The above-described conventional docking station has detected whether or not the data processing terminal is mounted using a mechanical switch, to control application of a voltage to the power feeding terminal.
However, in the mechanical switch, erroneous detection might be made by an object other than the data processing terminal. For this reason, in the above-described docking station, power might be fed to the power feeding terminal, in the state that the data processing terminal is not mounted.